Configure Derby to
use an in-memory database

If you use
Derby's in-memory database
facility, it is important to configure the following:

The size of the Java heap. The memory requirements for an in-memory
database should be similar to the memory requirements for using the file system,
plus the size of the user data.

The Derby page cache
size. For good performance, use no less than the default size of 1000 pages.
The data must pass through the page cache, even though the user data is already
stored in main memory. A larger page cache may improve performance at the
expense of increased memory usage. See
Increase the size of the data page cache for more information.

If you want to prevent
Derby from writing anything
to the derby.log file, use one of the derby.stream.error
properties (for instance, derby.stream.error.field).

For more information, see "Using in-memory databases" in the
Derby Developer's Guide.